Projection screen



Nov. 3, 1942. v I NEWMAN Re. 22,216

PROJECTION S GREEN Original Filed July 16, 193 2 Sheets-She et 1 mix'n INVENTOR Dal/id EMW/mm W M )Gal ATTORNEYJ Nov. 3, 1942. D. F. NEWMAN Re. 22,216

PROJECTION SCREEN Original Filed July 16, 1932 2 tsh et 2 ll/lllllrllirjirkklxlll1115 16));

INVENTOR David 1 Newman 17 5/ a9 4 PM Reissued Nov. 3, 1942 UNITED STATES PATENT err-Ice I raomcfifiz scaasf I I 7 1mm r. Newman, Mountain Lakes, N. 1., m to ,Lux Corporation, 7 a corporation of Delaware Original No. 2,122,8il0,- da

No. 822,980, Ill! 16, 19

issue April 29, 1940, S

11 Claims.

My invention relates to .a functionally and structurally improved projection screen.

My invention, in one of its important phases, relates to a projection screen having novel features particularly as regards the light-diffusing characteristics thereof.

My invention also relates to a novel screen for use in a projection system and particularly a rear projection system wherein the screen is disposed between the projector and the auditorium area.

Further objects, advantages and characteristics of my invention will become apparent from the go July 5. ms, Serial eriai No. 332,119

Application for rer ception of a suitable tool whereby said rods 1 may a desired degree so that it is desirable that the molding table T may be following detailed description taken in .connection with the accompanying drawings, in which:

Fig. l is a plan view, with parts omitted, of a molding table as constructed to produce one novel form of screen;

Fig. 2 is an elevational view, partly in section, of the table arrangement shown in Fig. 1;

Figs. 3, 4, 5, 6, 7 and 8 are. vertical sectional views, partly in elevation, illustrating progressive stages of my screen-forming method;

Fig. 9 is a perspective view of a straight edge which is used for shaping the upper surface of the screen; and

Fig. 10 is a perspective view of a part of a screen which illustrates a feature tion.

Referring particularly to Fig. 2, a suitable base has standards or uprights I a adapted to rest upon a. floor or other level surface. Carried by the base is a plate-like member 2 preferably of square or rectangular configuration and terminating along each side thereof in a downwardly directed flange 2a. Suitably secured to the flange 2a is an overflow trough or channel 3 which, preferably, comprises a discharge outlet 4.

Upstanding from the aforesaid member 2 are a plurality of supports 5 each of which may comprise an enlarged base suitably secured to said member 2, asby a plurality of screws 6. Each of the supports 5 is provided with a vertical, internally threaded passage which receives, in threaded relation, a rod 1 formed preferably of suitable metallic material and carrying, at its upper end, a supporting member 8 formed preferably of hard rubber or other suitable electricity-insulating material. As shown particularly in Fig. 1, a plurality of the supporting members 8 are thus provided and these are disposed preferably in symmetrical relation. The supporting members 8, at their upper ends, support a molding table T formed from glass, or other suitable material. Each ofthe rods 1, at the lower end thereof, is suitably fashioned as indicated at 1a. for the remaintained well above .room the molding operation. To

temperature during this end, there may be utilized a heating arrangement for said table T. A plurality of standards III are provided which upstand from the'aforesaid member 2 and,

\ at their upper ends, support a plate-like memof the invenher H which is I la for free extension therethrough of the respective aforesaid supporting members I. As shown particularly in Figs. 1 and 2, the member ll, along opposite edges thereof and substantially at the middle thereof carries strips I! of suitable insulating material, as hard rubber or the like. Upstanding from each strip I! are a plurality of spaced members It around and on which a suitable electrical conductor II, as nichrome, is spirally arranged, the ends of said conductor il being adapted for association with a suitable source of electrical energy.

As shown on the drawings, the table 'r is preferably either square or rectangular. Adapted for association with the table T is a. frame F'which conforms in configuration substantially with that of the table T although enclosing a somewhat greater area as shown particularly in Fig. 1.

The frame F is adapted to have a suitable fabric sheet S secured thereto in suitable taut condition as shown in Fig. 3. For thus securing the fabric sheet S to the frame F, there may be utilized tacks II, or the like. The fabric sheet 8 may be of any suitable character such, for example, as georgette crepe or knit fabric.

with the fabric sheet 8 secured to the frame F as shown in Fig. 3, the combined frame and sheet may be associated with the table T as'shown particularly in Figs. 1 and 4. In so doing, said fabric sheet 8, which preferably is slightly greater in area than that of the table T, comes to rest upon the latter, the frame F being suspended in space and supported solely by the fabric sheet 8. In this manner, said fabric sheet 8 is maintained under suitable tension in viscous material may now eachrod1maybe.

provided with suitable passages direct contacting. relamanner.

,tageously applied to the'screen surface by an air In Fig. 5, I have illustrated the screen in its partly completed condition as it exists after a layer of viscous screen-forming aterial M has. been more or, less evenly applied and over the fabric sheet as the latter rests upon the table T. The character of this screen-forming material will be hereinafter particularly described.

After the aforesaidviscous material has been deposited on the fabric sheet S'as described above,

it should be brought to substantially the thickness which the screen is to have when completed. This operation may be performed in any suitable man ner. As herein illustrated; a device A is thus utilized, Fig. 9, this device comprising a bar ll having a plane lower surface, said bar ll having runners 11 attached thereto adjacent opposite ends thereof. The runners H are adapted to rest upon the fabric sheet S and table T, the distance between therunners Il determining one transverse. dimension of the screen and the distance between the lower surface of the bar II and the upper surface of the table T determining substantially the final thickness of the completed screen; Accordingly, with the device A positioned as shown in Fig. 6, it is moved across the table T transversely of the direction in which the bar It extends whereby the runners I! track substantially parallel grooves in the layer of screen-forming material and the upper surface of the latter is brought to plane configuration. The screen as itexists at the completion of this operation is shown inFig. 'I.

In accordance with an important phase of my invention, suitable comminuted light-diffusing material; as finely divided glass, is applied to the upper'surface of the partially completed screen as it rests upon the table T. It is highly desirable that this light-diifusing material be thus applied to the screen while said screen is in plastic condition. When thus applied, the light diffusing material adheres tb or unites with the screen in a highly advantageous and practical Said light-diffusing material is advangun or in other suitable manner whereby a layer L thereof is formed on the upper screen surface as shown in Fig. 8. After the upper surface of the screen has been suitably covered by the aforesaid light-diffusing material and after the proper time interval has elapsed any excess or non-adhering material may be brushed or blown away whereby the upper screen surface retains only a relatively thin coating of said light-diffusing material.

Ordinarily, screens of the character herein described and claimed are utilized for rear projection purposes. Under such circumstances, the aforesaid viscous screen-forming material should be of. such character that the completed screen has the desired degree of tran'slucency. Any suit able screen-forming material may thusbe utilized such, for example, as disclosed in Payne- Newman U. S. Patent No. 1,881,128, dated Oct. 4, 1932. If the screen-forming material is to be of the character just stated,.the screen body material may comprise suitably proportioned amounts of gelatine, glycerine and water with which theremay be combined or associated one or more agents imparting a desired characteristic or characteristics to the completed screen. Thus, there may be incorporated in the screen-forming body material a light-diffusing agent, a light-filtering agent, and an agent having germicidal, bactericidal, fungicidal and/or preservative qualities, and a curing agent, it being distinctly undera'aaie stood, however, that the use of one or more of these agents is optional.

After the screen has beencompleted to the extent hereinbefore described, it may be allowed to cool. trimmed to a desired size and a suitable binding applied theretoas desired.

In lieu of screen body material formed princibe formed from other suitable material such, for example, as cellulose-acetate material as described in my United States Patent Number 2,034,382, dated December 17, 1935. With material of the character last noted, the table may remain at room ,temperature during the screenformin operation.

When cellulose-acetate material, or equivalent,

I is thus utilized as the screen body, the aforesaid comminuted light-diffusing material maybe applied to the upper surface at such time as may ,be suitable, provided, however, that such surface should be of such character that some of the applied comminuted material adheres thereto in a desired manner.

An important feature of the present invention is illustrated in Fig. 10 which illustrates the fabric sheet SI asformed from georgette crepe. Fabric of this character is characterized by having internal bands, so called, and other irregularities rendering the fabric somewhat objectionable for screen uses because causing said screen to be of non-uniform appearance during screen, Lhave discovered that a proper application. of .the aforesaid comminuted light-diffusing materials substantially or entirely eliminates non-uniform screen appearance during projection.. In Fig. 10, I have indicated the aforesaid internal band and irregularities at a, the comminuted light-diffusing material being. shown at b as blanketing said internal bandand irregularities.

:The hereinbefore described fabric sheets. S or SI serve as supports to impede or prevent sag of the screen when it is suspended vertically for projection purposes. These fabric sheets in a desired manner function to diffuselight passing through the screen. The advantages of the layer of comminuted light-diffusing material L have been in part heretofore explained. Further, by

using such comminuted material, it becomes pracas stated, may be included in the. translucent screen-forming material. I have demonstrated that a screen constructed in accordance with my present invention has a higher light-transmission factor than do screens of the prior art.

Although I have illustrated and described the fabric sheets S and SI and the layer of comminuted material L as on opposite sides of the screen, it shall be understood that my invention is not to be thuslimite'cl. If desired, said fabric sheets and the layer of comminuted material may be disposedon, the same sideof the sheet of translucent material, the layer of comminuted material preferably being outermost.

While the invention has been described with respect to certain particular preferred examples which give satisfactory results, it will be understood by those.skilled in the art after understanding th invention, that various changes and modifications may be' made without departing from the spirit and scope of the invention and it is in- Thereafter, the edges of the screen may be projection. when such a fabric sheet SI is included in the tended therefore in the appended claims to cover all such changes and modifications.

What is claimed as new and desired to be secured by Letters Patent is:

1. A projection screen comprising a sheet-like translucent body, and a plurality of layers of light-diflusing material associated with said translucent body. one of said layers being a fabric sheet and another of said layers being formed from comminuted material.

2. A projection screen comprising a translucent body, a fabric sheet of irregular weave associated with said translucent body, and a layer of comminuted light-diffusing material on one face of said translucent body, the density of said comminuted material being suillcient to preclude objectionable observation of the irregular weave condition of said fabric during projection of a light beam through the screen.

3. A projection screen comprising a translucent body formed from viscou material, a sheet of georgette crep associated with said translucent body, and a layer of comminuted light-diffusing material on one face of said translucent body, the density of said comminuted material being suflicient to preclude objectionable observation of irregularities in the weave of said sheet of crepe during projection of a light beam through the screen.

T 4. A projection screen comprising a sheet-like translucent body, a light-difiusing agent substantially uniformly incorporated therein, and a plurality of layers of light-diffusing material associated with said translucent body, one 01 said layers being a fabric sheet and another or said layers being formed from comminuted material.

5. A projection screen comprising a sheet-like translucent body, a light-difl'using agent substantially uniformly incorporated therein, and a plurality of layers of light-diflusing material associated with said translucent body, one of said layers being a fabric sheet and another of said layers being formed from comminuted material,

the comminuted material being secured to the translucent body by the adhesive action of said translucent body.

6. A projection screen comprising a sheet-like translucent body, and a plurality of layers .of light-diffusing material associated with said translucent body, one of said layers being a tabric sheet and another Of said layers being formed from comminuted material, th comminuted ma-.

terial being adhesively secured on on exterior face of said translucent body.

'7. A projection screen comprising a sheet-like translucent body, and a plurality of layers of light-diil'using material associated with said translucent body, one of said layersbeing a fabric sheet and another of said layers being formed from comminuted material, the comminuted material being secured to the translucent body by the adhesive action of said translucent body.

, 8. A projection screen comprising a sheet-like translucent body, a light-diffusing agent substantially uniformly incorporated therein, and a plurality of layers of light-diiiusing material associated with said translucent body, one of said layers being a fabric sheet embedded in said translucent body and another of said layers being formed from comminuted glass, the comminuted glass being secured to the translucent body by the adhesive action of said translucent body.

9. A translucent projection screen comprising, a base 01' substantially transparentmaterial free from a light diffusing ingredient in the body thereof, an array of minut light refracting parminute particle protruding from one side of said base for rendering the screen translucent, and a binder of cellulose ester material for binding said particles to said base.

11. A translucent projection screen according to claim 10 comprising a coating of light diffusing material on one surface oi'said screen.

DAVID F. NEWMAN. 

